Underfeed stoker



May 1 1923. E,453,892

P. E. SMHTH UNDERFEED STOKER Filed Feb. 21. 1922 3 Sheets-Sheei-J May 1, 1923. 1,453,892 P. E. SMITH UNDERFEED. STOKER Filed Feb. 21. 1922 s Sheets-Sham; 2

' May 1, 1923.

P. E. SMITH UNDEHFEED STCKER Filed Feb. 21

1922 3 Sheets-Sheet 5 Patented May 1. 1923.

PATENT Ol l ltiE.

PETER 1" EMITI-L OF PHILADELPHIA, PENNSYLVANIA.

UNDEHFEETD STUKEIR.

Application filed February 21, 1922.

To all to/tom it may concern Be it known that I, PETER lil. Sarina-r, a citizen of the United States, residing in llhiladelphia, Pennsylvania, have invented tin-- derfeed Stoker's, of which the following is a specification.

One object of this invention is to provide a stoker of the single retort, center-underfeed type, with novel means for delivering; air under pressure and feeding the fuel, the arrangement and proportions of the parts being such that said fuel shall be completely consumed with a minimum of air.

Another object of the invention is to provide a stoker of the above type including tuyere plates of such design that interference with the operation of the stoker by sittings through said plates or between the tuyerc boxes shall be practically eliminated and in which the frictional resistance to the move ment of the tuyere plates shall be reduced to a minimum.

I further desire to provide a stoker with novel means whereby the volume and pressure of the air delivered may be adjusted at will toniost elliciently burn the fuel and in which the loss of heat due to excess of air shall. be reduced to a minimum ;----the construction being such as to effectually prevent such flow of air as will cause burnii'ig out of the tuyere plates or their supporting structures.

I also desire to provide an under-feed stoker with a novel arrangement of parts for causingair from a source to be delivered under high pressure to certain portions of said stoker and under relatively lower pres sure to other parts thereof, the invention contemplating novel means whereby the supply of low pressure air may be conveniently governed.

Another object of my invention is to pro vide a. stolrer of the above noted type having such an arrangement of parts as will insure a minimum of repairs and facilitate re moval of ashes and refuse ;the device more especially including tuyere plates of novel form and mounting, in combination. with novel means for supporting and actuating said plates.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had to the accompanying drawings, in which,

Serial NO. 538,244.

Fig. 1 is a diagramn'iatic plan of a stoker constructed in accordance with my invention;

Fig. 2 is a transverse vertical section on the line 2 2, Fig. 1;

Fig. is a plan on a larger scale than Figs. 1 and 2, illustrating the detail construction of one of the tuyere plates and of the supporting structure for an adjacent plate;

big. at is a vertical section on the line 4. i Fig. 3; and

Fig. 5 is a transverse section on the line In the abov drawings, 2 represents a suitable foundation on which built the setting 1 for the boiler to which my invention is to be applied. This setting encloses or defines a chamber substantially rectangular in horizontal section and has extending across it a horizontal retort 3 to which fuel is supplied by any suitable means. From this retort said fuel is delivered laterally in opposite directions over two series of tuyere plates hereafter described in detail.

Immediately under said retort and like it extending transversely between opposite walls of the setting, is a chamber 4: supplied with air under pressure from a suitable blower or compressor, and this chamber is defined by a pair of parallel walls 5 project-- ing upwardly from the foundation 2. Each of these walls carries or includes vertical partition members 6 extei'iding to a height slightly below the top of the retort 3 and like said walls 5, running from one side to the other of the setting Between each of the partitions 6 and the side walls 1 of the setting and parallel thereto is mounted a beam or girder 7 serving to support the lower ends of a series of par allel hollow frames 8 of angular cross tion, whose upper ends are supported in any suitable manner, in the present instance upon one of the longitudinal edges of the retort 3, so that they extend substantially at right angles to the latter. There is thus a series of frai'nes on each side of said stolrer and the individual frames fit together as in dicated in 5 so as to form a series of elongated, open topped tuyere boxes 9 extending outwardly from the retort 3 toward the side walls 1.

it the lower end of each of the frames EJU lUS

8 is a fiat-topped projecting ledge 10 and between the line of these ledges and the adjacent wall 5 ismounted a series of dumping plates 11, preferably carried upon and fixed to a shaft 12 rotatably mounted in the end walls 1 and operable by any suitable means (not shown) for the purpose of permitting said plates to swing downwardly and dump into the ash pit 13 under them the ashes which may have accumulated thereon.

Adjacent the upper end of each of the tuyere boxes formed by the frames 8 is a transverse, substantially vertical partition 14 near which there is formed in the bottom of each frame an opening communicating directly with the air chamber a. The flow of air through these openings 15 into the several tuyere boxes is controlled by a gr d or sliding valve plate 16 mounted in suitable guideways on the frames 8 and provided with openings 17 which may be moved into register with the openings 15 or so adjusted as to completely cut off the flow of air from the chamber l into the tuyere boxes. The partitions 14 of each frame form with the upper ends thereof high pressure air chambers whose bottoms are open and there fore in direct communication with the upper. end of the air chamber 4 and these ends, which form continuations of the side walls of the retort, have formed in them outwardly flaring passages 18 whereby air under relatively high pressure may be delivered directly into the fuel in the upper part of the retort.

The otherwise open or top face of each of the stationary tuyere boxes is normally closed by an elongated, longitudinally reciprocable tuyere plate 19 whose lower end is offset so as to rest upon the ledge 10 of one of the frames 8 and whose upper end formed to slidably engage the flat face of the top 20 of the high pressure air chaml'ier 21' at the upper end of each tuyere box. Each of these tuyere plates has at opposite sides hooked lugs 22 extending under retaining or locking projections 23 on the side walls of the frames 8 so as to prevent them moving vertically while permitt ng their free longitudinal moven'icnt. Each of said. tuyere lates has formed in it a series of relatiy e y narrow. vertically and rearwardly extending slots 24 constituting tuyere ope-nings for the delivery of air from the tuyere boxes and in addition there are air passages 25 in the top plate 20 which in certain positions of the tuyere plate. communicate with tuyere openings 26 and 27 therein.

For the purpose of longitudinally recipro eating each of the several tuyere plates l mount a lever 28in the bottom of each of the frames or tuyereboxes 8 in such position that one arm thereof extends into a recess in a lug 29 projecting down from the under side of the upper end of the tuyere plate.

while a second arm extends between the forks of an operating arm 30 fixed on a shaft 31 extending parallel with the line of the retort and periodically oscillated through an angle of 60, for example, by any suitable mechanism (not shown).

With the above described arrangement of parts, air under pressure is delivered to the chamber 4 from a suitable source such as a blower or compressor and fuel is likewise fed into the retort 3 from one or both ends thereof so that it rises in saidretort and flows down over the tuyere plates 19 on the opposite sides thereof. After the fuel has been ignited, the air under the relatively high pressure at which it is delivered to the chamber 4, flows into the high pressure chambers 21 of the tuyere boxe and is dolivered therefrom through the tuycre openings 18 into the retort and also through the openings 25, 26 and 27. when tuyere plates 19 have been brought into the positions shown in Fig. 4. These plates are reciprocated on their supporting frames b oscillation of the shaft 31 and tend to cause movement of the fuel away from the retort downwardly to ard and onto the dumping plates 11.

The grid or valve plate 16 is so adjusted as to supply air at a relatively low pressure to the main portions of the tuyere boxes and this air is delivered through the tuyere openings 24 into the fuel as said plates are reciprocated, thus insuring the complete burning of the fuel before it reaches the dumping plates 11. It will be understood that the regulating valve or grid 16 is aljusted by any suitable means so as to reg ulate the amount of air delivered through the openings 2.4. to that required for the proper combustion of the fuel. Owing to the shape and disposition of the tuyere openings 24 and to the outwardly flowing currents of air passing through them. there is no sifting of the finer particles of fuel or ash into the tuyere boxes.

Moreover since the ledges 10 of the frames 8 are completely covered by the lower ends of the tuyere plates. the friction between these elements is reduced to a minimum. since particles of fuel and ash are not likely to get between them. Vhile the plates 19 have limited bearing on the vertical side members of the frames 8, frictional resistance due to particles of fuel getting between these parts is relatively small and the same is true of the coacting surfaces of the top portions 20 of the frames and the upper ends of the tuyere plates. The latter may be readily removed and replaced when this is desi able for any purpose and they may be designed to suit the grade of fuel used in the stoker.

Owing to the possibility of accurately regulating the amount of air through the Sll low pressure chambers of the tuyere boxes, a minimum of air may be used, and the regulation may be such as to cause the complete consumption of the fuel. The structure as a whole is relatively simple and may be so constructed as to require a minimum of repairs.

l rom the above description it will be noted that it is not possible for the air delivered from the source of supply to take such a, course as will permit or cause burning or overheating of the tuyere plates or of their supporting frames, but on the contrary the arrangement is such that these parts are n'iaintained relatively cool and in operative condition.

I claim:

1. The combination in a stoker of a retort; a series of stationary air boxes extending; at right angles to said. retort; tuyere pla tes longitudinally slidable on the air boxes respectively; means for supplying air under pressure to the air boxes; and means for reciprocating the tuyere plates.

2. The combination in a stoker of a re tort; a series of coasting frames forming air boxes extending at right angles to said retort; a tuyere plate slidably mounted on each of the air boxes; means for reciprocating the tuycre plates toward and from the retort; and means for supplying air under pressure to the air boxes.

3. The combination in a stolrer of a re tort; a series of stationary air boxes extending at right angles to the retort; tuyere plates longitudinally slidable on the air boxes respectively; an air supply chamber; and means for controlling the flow of air from said chamber to the air boxes.

l. The combination in a stoker of a retort; a series of stationary air boxes extending; at right angles to the retort; tuyere plates longitudinally slidable on the air boxes respectively; an air supply chamber; and means for controlling the flow of air from said chamber to the air boxes consisting: of a valve member exteni'lingjr in a line at rigrht angles to the air boxes.

55. The con'ibination in a stolrer of a retort; an air supply clnnnber under the retort; a, series of air boxes amending; at right angles to the retort and having aligned openings respectively communicating with the air chamber; tuyere plates respectively slidable longitudinally on said air boxes; means for reciprocating said tuyere plates; and a valve member coactingr with the openingrs of the air bones and adjustable to povera the flow of air from the chamber thereto.

6. The combination in a stoli'er of a retort; a series of interlocked frames forming elongated, air boxes extending in lines at ri 'ht angles to said retort; tuyere plates [ably mounted. on said boxes respectively and locked thereto against vertical movement; means for reciprocating said tuyere plates on the air boxes; and means for supplyingair under pressure to the air boxes;

7. The combination in a stoker of a series of frames of angular cross section coat-ting to form a series of open topped elongated air boxes; a retort extending transversely of the upper ends of said air boxes; tuyere plates mounted on the frames and iorming tops for the same; with means for reciprocating said tuyere plates toward and from the retort.

8. The combination in a stolrer of a retort; a series of air boxes extending at right angles to the retort and each having a transverse partition adjacent its upper end dividing' it into two chambers; a tuyere plate slidably mounted on each of said boxes; an air supply ehan'il'ier normally communis eating with both of the chambers of each of the air boxes; and a slidable valve member governing the how of air from said chamher into one of the chambers of each of the boxes.

9. The combination in a stoker of a retort; a series of air boxes extending at right angles thereto and each having a partition dividing it into two chambers of which the smaller is adjacent the retort; an air supply chamber communicating with both chambers of each of the air boxes; a tuyere plate reciprocable on each of the air boxes and having air delivery openings; a valve member movable at right angles to the lines of the air boxes and formed to control the flow of air from the supply chamber to the larger chambers thereof; and means for reciprocating the tuyere plates.

10. The combination in a Stoker of a retort; air boxes extending at right angles to said retort; a series of agitator tuyere plates slidably mounted on said boxes; an oscillatory shaft; and a series of levers for transmititng movement from said shaft to said agitator plates respectively.

11. The combination in a stoke]? of a retort; an air supply chamber under the same; an ash pit; a series of elongated air boxes extended at right angles from the retort over the ash pit; dumping plates at the lower ends of the air boxes; agitator tuyere plates mounted on the air boxes and means for reciprocating said plates toward and from the retort.

12. The combination in a stoker of a retort; a series of air boxes made up of frames of L-shaped section; agitator tuyere plates slidable on the top edges of adjacent parts of said frames; and means for longitudinally reciprocating said plat s.

118. The combination in a stoker of a retort; a of elongated closed bottom sta-- tionary air boxes extending substantially at 'ht anpjles to said, retort; elongated perforated plates respectively closing the tops of said boxes; means for supplying air under pressure to the boxes; and means for reeiproeating; the plates toward and from the retorts.

14. The combination in a Stoker of a retort; a series of elongated closed bottom stationary air boxes extending substantially at right angles to said retort; elongated perforated plates respectively closing the tops of said boxes; means for supplying air under pressure to the boxes; means for reeiplocating the plates toward and from the retorts; with a partition in tflCl) of the air boxes dividing it into two ehambeis of which one has openings into the retort.

PETER E. SMITH. 

